CELLS QUIZ Flashcards
Cell Theory
living things are made of cells
unit of structure and function
smallest unit of life.
Pre- Existing cells have come from other cells.
Evidence for Cell theory
a. All living things are made of cells:
When living things are observed under the microscope they consistently appear to be composed of cells.
Muscle cells: challenges the idea that a cell has one nucleus
Fungal Cells: challenges the idea that a cell is a single unit.
Protoctista: Challenges the idea that a cell is specialised to a single function. Yet, the protoctista can carry out all functions of life.
Cells are the smallest unit of life.
The cell is the smallest unit of organisation that can show all the characteristics of living processes.
Cells come only from other cells.
Cells carry out a form of cell division to form new cells. This process of cell replication in eukaryotes is called mitosis and in prokaryotes is called binary fission.
metabolism
which includes respiration the synthesis of ATP.
response
to a change in the environment
homeostasis
the maintenance and regulation of internal cell conditions.
growth
which for a unicellular organism means an increase in cell size and volume
reproduction
which for the unicellular organism is largely asexual through cell division to form a clone.
nutrition
which means either the synthesis of organic molecules or the absorption of organic matter.
molecules
1nm
viruses
10nm
bacteria
1 micro meter
organelles
up to 10 micro meters
most cells
up to 100 micro meters
SA to Volume
As the organism gets bigger its surface area : volume ratio decreases
Stem Cells
A stem cell is able to divide but has not yet expressed genes to specialise to a particular function. Under the right conditions stem cells can be induced to express particular genes and differentiate into a particular type of cell.
Therapeutic stem cells
Therapeutic Cloning: This is a method of obtaining ES cells from someone who has already been born. These stem cells can be used to treat the individual without generating an immune response. The human body recognizes and attacks foreign cells, including stem cells. This is a serious barrier to stem cell therapy.
Pro Cell Wall:
maintaining/determining cell shape`
pro Plasma membrane:
Controls the entry and exit of substances, pumping some of them in by active transport.
pro Cytoplasm
Contains all the enzymes needed for all metabolic reactions, since there are no organelles.
PRO Ribosome
The smaller (70 S) type are all free in the cytoplasm, not attached to membranes (like RER). They are used in protein synthesis which is part of gene expression.
pro Nucleoid
Is the region of the cytoplasm that contains DNA. It is not surrounded by a nuclear membrane. DNA is always a closed loop (i.e. a circular), and not associated with any proteins to form chromatin.
pro Flagella:
These long thread like attachments are generally considered to be for movement. They have an internal protein structure that allows the flagella to be actively moved as a form of propulsion. The presence of flagella tends to be associated with the pathogenicity of the bacterium. The flagella is about 20nm in diameter. This structure should not be confused with the eUkaryotic flagella seen in protoctista.
pro Pilli:
These thread like projections are usually more numerous than the flagella. They are associated with different types of attachment. In some cases they are involved in the transfer of DNA in a process called conjugation or alternatively as a means of preventing phagocytosis.
free ribosomes
the free ribosome produces proteins for internal use within the cell.
Rough endoplasmic reticulum
rER form a network of tubules with a maze like structure.
In general these run away from the nucleus
The ‘rough’ on the reticulum is caused by the presence of ribosomes.
Proteins made here are secreted out of the cel
Lysozyme
Functions include the digestion of old organelles, engulfed bacteria and viruses.
golgi aparatus
Process and package the macromolecules such as proteins and lipids
Processing of proteins for secretion
Transporting lipids around the cell
Creating lysosomes
mitochondria
Oxygen is consumed in the synthesis of ATP on the inner membrane
nucleus
controls the cells functions through the expression of genes
Prokaryote VS. Eukaryote
pro: no nucleus naked loop
euk: nucleus w/ DNA
pro:DNA in cytoplasm
Euk: DNA in a nuclear envelope
pro:no mitochondria
euk: mitochondria
pro:small ribosomes
euk : large ribosomes
Animals VS. Plants
Plants have chloroplast anmials dont
plant cells are usaully boxed while animals round
animals store glycogen plants starch
extracurricular component
Plant Cell Wall maintains cell shape, prevents excessive water intake, holds plant up against force of gravity
extracurricular component 2
animal cells secrete glycoprotiens that form the exracurricular matrix, helps with support, adhesion , and movement
